[CMake] Introduce libLLVM.so as LLVM_ENABLE_SHARED

[chapuni]

Summary

Note, this includes; http://llvm-reviews.chandlerc.com/D2941

Why using OBJLIB?

• --whole-archive is available only for GNU ld. Rather, I chose linking whole OBJLIBs.
• No need to create *.a(s). Archive files may be created in parallel.

Why introducing DEPENDS instead of add_dependencies?

• add_dependencies(target) works only for the target. Implicitly generated obj.LLVM*** are required to add deps to generated files.

Why llvm-tblgen and clang-tblgen are tweaked?

• They should be built out of LINK_COMPONENTS with -static.

Why LLVM_ENABLE_SHARED turns off LLVM_DEAD_STRIP?

• I think -ffunction-sections would not make sense for the big libLLVM.so.

TODO

• libLLVM-3.5.so may have VERSION.
• Consider c-index-test with libclang. With this, it requires "libclang.so libLLVM.so" in its command line to link it. If we could use -rpath-link, it might be simply "libclang.so" w/o libLLVM.so.
• Introduce Clang's big shared libraries.
• Introduce LLVM.dll for cygming.
• Introduce LLVM.dll for whole win32. (It would require dllexport/dllimport in public headers)

[chapuni]

I updated this BUILD_SHARED_LIBS-friendly.

• With LLVM_ENABLE_SHARED and BUILD_SHARED_LIBS, libLLVM.so behaves "convenient library" w/o any contents.
• Don't create obj.FOO if FOO is SHARED. (It would make building serialized, though)
• Prune DEAD_STRIP stuff. It was micro-optimization.

TODO:
With LLVM_ENABLE_SHARED and BUILD_SHARED_LIBS, a warning could be seen;

You have called ADD_LIBRARY for library LLVM_shared without any source files.
This typically indicates a problem with your CMakeLists.txt file

I have to add at least one dummy.cpp to appease it.

[chandlerc]

Really stale patch and not clear if this is really something folks are still interested in as there have been lots of changes to the build since.

Update and add me back (or start a fresh revision) if this is still something you want to pursue.

clang/utils/TableGen/CMakeLists.txt

-set(LLVM_LINK_COMPONENTS Support)
-
 add_tablegen(clang-tblgen CLANG
   ClangASTNodesEmitter.cpp
   ClangAttrEmitter.cpp
   ClangCommentCommandInfoEmitter.cpp
   ClangCommentHTMLNamedCharacterReferenceEmitter.cpp
   ClangCommentHTMLTagsEmitter.cpp
   ClangDiagnosticsEmitter.cpp
   ClangSACheckersEmitter.cpp
   NeonEmitter.cpp
   TableGen.cpp
   )

llvm/CMakeLists.txt

 include(config-ix)
 
 # By default, we target the host, but this can be overridden at CMake
 # invocation time.
 set(LLVM_DEFAULT_TARGET_TRIPLE "${LLVM_HOST_TRIPLE}" CACHE STRING
   "Default target for which LLVM will generate code." )
 set(TARGET_TRIPLE "${LLVM_DEFAULT_TARGET_TRIPLE}")
 
+if(NOT WIN32)
+  option(LLVM_ENABLE_SHARED "Build the big shared library libLLVM.so." OFF)
+endif()
+
 include(HandleLLVMOptions)
 
 # Verify that we can find a Python 2 interpreter.  Python 3 is unsupported.
 set(Python_ADDITIONAL_VERSIONS 2.7 2.6 2.5)
 include(FindPythonInterp)
 if( NOT PYTHONINTERP_FOUND )
   message(FATAL_ERROR
 "Unable to find Python interpreter, required for builds and testing.

llvm/cmake/modules/AddLLVM.cmake

else()
     if(BUILD_SHARED_LIBS AND NOT ARG_STATIC)
       set(ARG_SHARED TRUE)
     endif()
     if(NOT ARG_SHARED)
       set(ARG_STATIC TRUE)
     endif()
   endif()
 
+  set(build_objlib)
   # Generate objlib
   if(ARG_SHARED AND ARG_STATIC)
+    set(build_objlib TRUE)
+  endif()
+  if(LLVM_ENABLE_SHARED AND NOT ARG_SHARED)
+    set(build_objlib TRUE)
+  endif()
+
+  if(build_objlib AND NOT ARG_OBJLIBS)
     # Generate an obj library for both targets.
     set(obj_name "obj.${name}")
     add_library(${obj_name} OBJECT EXCLUDE_FROM_ALL
       ${ALL_FILES}
       )
     llvm_update_compile_flags(${obj_name})
     set(ALL_FILES "$<TARGET_OBJECTS:${obj_name}>")
 
function(llvm_add_library name)
 
   # Add the explicit dependency information for this library.
   #
   # It would be nice to verify that we have the dependencies for this library
   # name, but using get_property(... SET) doesn't suffice to determine if a
   # property has been set to an empty value.
   get_property(lib_deps GLOBAL PROPERTY LLVMBUILD_LIB_DEPS_${name})
 
+  if((ARG_LINK_COMPONENTS OR LLVM_LINK_COMPONENTS) AND TARGET LLVM_shared)
+    set(llvm_libs)
+    # FIXME: It may be PRIVATE since SO knows its dependent libs.
+    target_link_libraries(${name} PUBLIC
+      LLVM_shared
+      )
+  else()
     llvm_map_components_to_libnames(llvm_libs
       ${ARG_LINK_COMPONENTS}
       ${LLVM_LINK_COMPONENTS}
       )
+  endif()
 
   if(CMAKE_VERSION VERSION_LESS 2.8.12)
     # Link libs w/o keywords, assuming PUBLIC.
     target_link_libraries(${name}
       ${ARG_LINK_LIBS}
       ${lib_deps}
       ${llvm_libs}
       )
function(llvm_add_library name)
   if(LLVM_COMMON_DEPENDS)
     add_dependencies(${name} ${LLVM_COMMON_DEPENDS})
     # Add dependencies also to objlibs.
     # CMake issue 14747 --  add_dependencies() might be ignored to objlib's user.
     foreach(objlib ${objlibs})
       add_dependencies(${objlib} ${LLVM_COMMON_DEPENDS})
     endforeach()
   endif()
+
+  if(objlibs)
+    set_target_properties(${name} PROPERTIES LLVM_OBJLIBS ${objlibs})
+  endif()
 endfunction()
 
 macro(add_llvm_library name)
   if( BUILD_SHARED_LIBS )
     llvm_add_library(${name} SHARED ${ARGN})
   else()
     llvm_add_library(${name} ${ARGN})
   endif()
-  set_property( GLOBAL APPEND PROPERTY LLVM_LIBS ${name} )
 
   if( EXCLUDE_FROM_ALL )
     set_target_properties( ${name} PROPERTIES EXCLUDE_FROM_ALL ON)
   else()
+    set_property( GLOBAL APPEND PROPERTY LLVM_LIBS ${name} )
     if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY OR ${name} STREQUAL "LTO")
       install(TARGETS ${name}
         EXPORT LLVMExports
         LIBRARY DESTINATION lib${LLVM_LIBDIR_SUFFIX}
         ARCHIVE DESTINATION lib${LLVM_LIBDIR_SUFFIX})
     endif()
     set_property(GLOBAL APPEND PROPERTY LLVM_EXPORTS ${name})
   endif()
macro(add_llvm_executable name)
   add_dead_strip( ${name} )
 
   if (LLVM_EXPORTED_SYMBOL_FILE)
     add_llvm_symbol_exports( ${name} ${LLVM_EXPORTED_SYMBOL_FILE} )
   endif(LLVM_EXPORTED_SYMBOL_FILE)
 
   set(EXCLUDE_FROM_ALL OFF)
   set_output_directory(${name} ${LLVM_RUNTIME_OUTPUT_INTDIR} ${LLVM_LIBRARY_OUTPUT_INTDIR})
-  llvm_config( ${name} ${LLVM_LINK_COMPONENTS} )
+  if(LLVM_LINK_COMPONENTS)
+    if(TARGET LLVM_shared)
+      target_link_libraries(${name} LLVM_shared)
+    else()
+      llvm_config(${name} ${LLVM_LINK_COMPONENTS})
+    endif()
+  endif()
   if( LLVM_COMMON_DEPENDS )
     add_dependencies( ${name} ${LLVM_COMMON_DEPENDS} )
   endif( LLVM_COMMON_DEPENDS )
 endmacro(add_llvm_executable name)
 
 
 set (LLVM_TOOLCHAIN_TOOLS
   llvm-ar
macro(add_llvm_utility name)
   set_target_properties(${name} PROPERTIES FOLDER "Utils")
 endmacro(add_llvm_utility name)
 
 
 macro(add_llvm_target target_name)
   include_directories(BEFORE
     ${CMAKE_CURRENT_BINARY_DIR}
     ${CMAKE_CURRENT_SOURCE_DIR})
-  add_llvm_library(LLVM${target_name} ${ARGN} ${TABLEGEN_OUTPUT})
+  add_llvm_library(LLVM${target_name} ${ARGN})
   set( CURRENT_LLVM_TARGET LLVM${target_name} )
 endmacro(add_llvm_target)
 
 # Add external project that may want to be built as part of llvm such as Clang,
 # lld, and Polly. This adds two options. One for the source directory of the
 # project, which defaults to ${CMAKE_CURRENT_SOURCE_DIR}/${name}. Another to
 # enable or disable building it with everything else.
 # Additional parameter can be specified as the name of directory.

llvm/cmake/modules/HandleLLVMOptions.cmake

if (UNIX AND
     CMAKE_GENERATOR STREQUAL "Ninja")
   append("-fcolor-diagnostics" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
 endif()
 
 # Add flags for add_dead_strip().
 # FIXME: With MSVS, consider compiling with /Gy and linking with /OPT:REF?
 # But MinSizeRel seems to add that automatically, so maybe disable these
 # flags instead if LLVM_NO_DEAD_STRIP is set.
-if(NOT CYGWIN AND NOT WIN32)
+if(LLVM_ENABLE_SHARED OR CYGWIN OR WIN32)
+  set(LLVM_NO_DEAD_STRIP ON)
+else()
   if(NOT ${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
     check_c_compiler_flag("-Werror -fno-function-sections" C_SUPPORTS_FNO_FUNCTION_SECTIONS)
     if (C_SUPPORTS_FNO_FUNCTION_SECTIONS)
       # Don't add -ffunction-section if it can be disabled with -fno-function-sections.
       # Doing so will break sanitizers.
       check_c_compiler_flag("-Werror -ffunction-sections" C_SUPPORTS_FFUNCTION_SECTIONS)
       check_cxx_compiler_flag("-Werror -ffunction-sections" CXX_SUPPORTS_FFUNCTION_SECTIONS)
       append_if(C_SUPPORTS_FFUNCTION_SECTIONS "-ffunction-sections" CMAKE_C_FLAGS)

llvm/cmake/modules/TableGen.cmake

add_custom_command(OUTPUT ${CX_NATIVE_TG_DIR}/CMakeCache.txt
     COMMENT "Configuring native TableGen...")
 
   add_custom_target(ConfigureNativeTableGen DEPENDS ${CX_NATIVE_TG_DIR}/CMakeCache.txt)
 
   set_directory_properties(PROPERTIES ADDITIONAL_MAKE_CLEAN_FILES ${CX_NATIVE_TG_DIR})
 endif()
 
 macro(add_tablegen target project)
-  set(${target}_OLD_LLVM_LINK_COMPONENTS ${LLVM_LINK_COMPONENTS})
-  set(LLVM_LINK_COMPONENTS ${LLVM_LINK_COMPONENTS} TableGen)
+  set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${LLVM_TOOLS_BINARY_DIR})
+
   add_llvm_utility(${target} ${ARGN})
-  set(LLVM_LINK_COMPONENTS ${${target}_OLD_LLVM_LINK_COMPONENTS})
 
   set(${project}_TABLEGEN "${target}" CACHE
       STRING "Native TableGen executable. Saves building one when cross-compiling.")
 
   # Upgrade existing LLVM_TABLEGEN setting.
   if(${project} STREQUAL LLVM)
     if(${LLVM_TABLEGEN} STREQUAL tblgen)
       set(LLVM_TABLEGEN "${target}" CACHE
if( ${${project}_TABLEGEN} STREQUAL "${target}" )
         COMMENT "Building native TableGen...")
       add_custom_target(${project}NativeTableGen DEPENDS ${${project}_TABLEGEN_EXE})
       add_dependencies(${project}NativeTableGen ConfigureNativeTableGen)
 
       add_dependencies(${target} ${project}NativeTableGen)
     endif()
   endif()
 
+  target_link_libraries(${target} LLVMSupport LLVMTableGen)
   if( MINGW )
     if(CMAKE_SIZEOF_VOID_P MATCHES "8")
       set_target_properties(${target} PROPERTIES LINK_FLAGS -Wl,--stack,16777216)
     endif(CMAKE_SIZEOF_VOID_P MATCHES "8")
   endif( MINGW )
   if (${project} STREQUAL LLVM AND NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
     install(TARGETS ${target}
             EXPORT LLVMExports
             RUNTIME DESTINATION bin)
   endif()
   set_property(GLOBAL APPEND PROPERTY LLVM_EXPORTS ${target})
 endmacro()

llvm/lib/Analysis/CMakeLists.txt

add_llvm_library(LLVMAnalysis
   ScalarEvolutionAliasAnalysis.cpp
   ScalarEvolutionExpander.cpp
   ScalarEvolutionNormalization.cpp
   SparsePropagation.cpp
   TargetTransformInfo.cpp
   Trace.cpp
   TypeBasedAliasAnalysis.cpp
   ValueTracking.cpp
+  DEPENDS intrinsics_gen
   )
 
-add_dependencies(LLVMAnalysis intrinsics_gen)
-
 add_subdirectory(IPA)

llvm/lib/Analysis/IPA/CMakeLists.txt

 add_llvm_library(LLVMipa
   CallGraph.cpp
   CallGraphSCCPass.cpp
   CallPrinter.cpp
   FindUsedTypes.cpp
   GlobalsModRef.cpp
   IPA.cpp
   InlineCost.cpp
+  DEPENDS intrinsics_gen
   )
-
-add_dependencies(LLVMipa intrinsics_gen)

llvm/lib/Bitcode/Reader/CMakeLists.txt

 add_llvm_library(LLVMBitReader
   BitReader.cpp
   BitcodeReader.cpp
   BitstreamReader.cpp
+  DEPENDS intrinsics_gen
   )
-
-add_dependencies(LLVMBitReader intrinsics_gen)

llvm/lib/CodeGen/AsmPrinter/CMakeLists.txt

 add_llvm_library(LLVMAsmPrinter
   ARMException.cpp
   AsmPrinter.cpp
   AsmPrinterDwarf.cpp
   AsmPrinterInlineAsm.cpp
   DIE.cpp
   DIEHash.cpp
   DwarfAccelTable.cpp
   DwarfCFIException.cpp
   DwarfDebug.cpp
   DwarfException.cpp
   DwarfUnit.cpp
   ErlangGCPrinter.cpp
   OcamlGCPrinter.cpp
   Win64Exception.cpp
   WinCodeViewLineTables.cpp
+  DEPENDS intrinsics_gen
   )
-
-add_dependencies(LLVMAsmPrinter intrinsics_gen)

llvm/lib/CodeGen/CMakeLists.txt

add_llvm_library(LLVMCodeGen
   TargetLoweringBase.cpp
   TargetLoweringObjectFileImpl.cpp
   TargetOptionsImpl.cpp
   TargetRegisterInfo.cpp
   TargetSchedule.cpp
   TwoAddressInstructionPass.cpp
   UnreachableBlockElim.cpp
   VirtRegMap.cpp
+  DEPENDS intrinsics_gen
   )
 
-add_dependencies(LLVMCodeGen intrinsics_gen)
-
 add_subdirectory(SelectionDAG)
 add_subdirectory(AsmPrinter)

llvm/lib/CodeGen/SelectionDAG/CMakeLists.txt

add_llvm_library(LLVMSelectionDAG
   SelectionDAG.cpp
   SelectionDAGBuilder.cpp
   SelectionDAGDumper.cpp
   SelectionDAGISel.cpp
   SelectionDAGPrinter.cpp
   ScheduleDAGVLIW.cpp
   TargetLowering.cpp
   TargetSelectionDAGInfo.cpp
+  DEPENDS intrinsics_gen
   )
-
-add_dependencies(LLVMSelectionDAG intrinsics_gen)

llvm/lib/ExecutionEngine/Interpreter/CMakeLists.txt

 # Make sure that the path to libffi headers is on the command
 # line. That path can be a compiler's non-default path even when
 # FFI_INCLUDE_DIR was not used, because cmake has its own paths for
 # searching for headers (CMAKE_SYSTEM_INCLUDE_PATH, for instance):
 if( FFI_INCLUDE_PATH )
   include_directories( ${FFI_INCLUDE_PATH} )
 endif()
 
 add_llvm_library(LLVMInterpreter
   Execution.cpp
   ExternalFunctions.cpp
   Interpreter.cpp
+  DEPENDS intrinsics_gen
   )
 
 if( LLVM_ENABLE_FFI )
   target_link_libraries( LLVMInterpreter ${FFI_LIBRARY_PATH} )
 endif()
-
-add_dependencies(LLVMInterpreter intrinsics_gen)

llvm/lib/IR/CMakeLists.txt

add_llvm_library(LLVMCore
   Type.cpp
   TypeFinder.cpp
   Use.cpp
   User.cpp
   Value.cpp
   ValueSymbolTable.cpp
   ValueTypes.cpp
   Verifier.cpp
+  DEPENDS intrinsics_gen
   )
-
-add_dependencies(LLVMCore intrinsics_gen)

llvm/lib/Transforms/IPO/CMakeLists.txt

add_llvm_library(LLVMipo
   Internalize.cpp
   LoopExtractor.cpp
   MergeFunctions.cpp
   PartialInlining.cpp
   PassManagerBuilder.cpp
   PruneEH.cpp
   StripDeadPrototypes.cpp
   StripSymbols.cpp
+  DEPENDS intrinsics_gen
   )
-
-add_dependencies(LLVMipo intrinsics_gen)

llvm/lib/Transforms/InstCombine/CMakeLists.txt

 add_llvm_library(LLVMInstCombine
   InstructionCombining.cpp
   InstCombineAddSub.cpp
   InstCombineAndOrXor.cpp
   InstCombineCalls.cpp
   InstCombineCasts.cpp
   InstCombineCompares.cpp
   InstCombineLoadStoreAlloca.cpp
   InstCombineMulDivRem.cpp
   InstCombinePHI.cpp
   InstCombineSelect.cpp
   InstCombineShifts.cpp
   InstCombineSimplifyDemanded.cpp
   InstCombineVectorOps.cpp
+  DEPENDS intrinsics_gen
   )
-
-add_dependencies(LLVMInstCombine intrinsics_gen)

llvm/lib/Transforms/Instrumentation/CMakeLists.txt

 add_llvm_library(LLVMInstrumentation
   AddressSanitizer.cpp
   BoundsChecking.cpp
   DataFlowSanitizer.cpp
   DebugIR.cpp
   GCOVProfiling.cpp
   MemorySanitizer.cpp
   Instrumentation.cpp
   ThreadSanitizer.cpp
+  DEPENDS intrinsics_gen
   )
-
-add_dependencies(LLVMInstrumentation intrinsics_gen)

llvm/lib/Transforms/ObjCARC/CMakeLists.txt

 add_llvm_library(LLVMObjCARCOpts
   ObjCARC.cpp
   ObjCARCOpts.cpp
   ObjCARCExpand.cpp
   ObjCARCAPElim.cpp
   ObjCARCAliasAnalysis.cpp
   ObjCARCUtil.cpp
   ObjCARCContract.cpp
   DependencyAnalysis.cpp
   ProvenanceAnalysis.cpp
+  DEPENDS intrinsics_gen
   )
-
-add_dependencies(LLVMObjCARCOpts intrinsics_gen)

llvm/lib/Transforms/Scalar/CMakeLists.txt

add_llvm_library(LLVMScalarOpts
   SROA.cpp
   Scalar.cpp
   ScalarReplAggregates.cpp
   SimplifyCFGPass.cpp
   FlattenCFGPass.cpp
   Sink.cpp
   StructurizeCFG.cpp
   TailRecursionElimination.cpp
+  DEPENDS intrinsics_gen
   )
-
-add_dependencies(LLVMScalarOpts intrinsics_gen)

llvm/lib/Transforms/Utils/CMakeLists.txt

add_llvm_library(LLVMTransformUtils
   FlattenCFG.cpp
   SimplifyIndVar.cpp
   SimplifyInstructions.cpp
   SimplifyLibCalls.cpp
   SpecialCaseList.cpp
   UnifyFunctionExitNodes.cpp
   Utils.cpp
   ValueMapper.cpp
+  DEPENDS intrinsics_gen
   )
-
-add_dependencies(LLVMTransformUtils intrinsics_gen)

llvm/lib/Transforms/Vectorize/CMakeLists.txt

 add_llvm_library(LLVMVectorize
   BBVectorize.cpp
   Vectorize.cpp
   LoopVectorize.cpp
   SLPVectorizer.cpp
+  DEPENDS intrinsics_gen
   )
-
-add_dependencies(LLVMVectorize intrinsics_gen)

llvm/tools/CMakeLists.txt

+if(LLVM_ENABLE_SHARED)
+  add_llvm_tool_subdirectory(llvm-shlib)
+endif()
+
 add_llvm_tool_subdirectory(llvm-config)
 
 add_llvm_tool_subdirectory(opt)
 add_llvm_tool_subdirectory(llvm-as)
 add_llvm_tool_subdirectory(llvm-dis)
 add_llvm_tool_subdirectory(llvm-mc)
 
 add_llvm_tool_subdirectory(llc)

llvm/tools/llvm-shlib/CMakeLists.txt

+get_property(llvm_libs GLOBAL PROPERTY LLVM_LIBS)
+list(REMOVE_ITEM llvm_libs LLVMTableGen gtest gtest_main)
+foreach(lib ${llvm_libs})
+  get_target_property(t ${lib} TYPE)
+  if("${t}" STREQUAL "STATIC_LIBRARY")
+    get_target_property(objlibs ${lib} LLVM_OBJLIBS)
+    foreach(objlib ${objlibs})
+      list(APPEND all_objlibs "$<TARGET_OBJECTS:${objlib}>")
+    endforeach()
+    # Collect dependent system libs.
+    get_target_property(dependent_libs ${lib} INTERFACE_LINK_LIBRARIES)
+    list(REMOVE_ITEM dependent_libs ${llvm_libs})
+    if(dependent_libs)
+      list(REVERSE dependent_libs)
+      list(INSERT all_dependent_libs 0 ${dependent_libs})
+    endif()
+  else()
+    list(INSERT all_dependent_libs 0 ${lib})
+  endif()
+endforeach()
+list(REMOVE_DUPLICATES all_dependent_libs)
+list(REVERSE all_dependent_libs)
+
+add_llvm_library(LLVM_shared SHARED
+  OUTPUT_NAME "LLVM-3.5"
+  OBJLIBS ${all_objlibs}
+  LINK_LIBS ${all_dependent_libs}
+  )
+
+set_target_properties(LLVM_shared PROPERTIES LINKER_LANGUAGE "CXX")

llvm/utils/TableGen/CMakeLists.txt

-set(LLVM_LINK_COMPONENTS Support)
-
 add_tablegen(llvm-tblgen LLVM
   AsmMatcherEmitter.cpp
   AsmWriterEmitter.cpp
   AsmWriterInst.cpp
   CallingConvEmitter.cpp
   CodeEmitterGen.cpp
   CodeGenDAGPatterns.cpp
   CodeGenInstruction.cpp